NetBeans IDE is open source, available for free from http://www.netbeans.org, runs on all modern operating systems, and include a popular GUI builder that can be used to develop GUIs for Java applications..

You can download the NetBeans tutorial here and the NetBeans GUI builder tutorial here

Create a new project

Code editor showing error message with the red X. Move the mouse over it to see the error message.

Fix the error. Run by clicking F6